This hotfixes fixes a problem where the network connection of a running Hyper-V virtual machine may be lost under heavy outgoing network traffic on a computer that is running Windows Server 2008 R2 SP1.

Consider the following scenario:

You install the Hyper-V role on a computer that is running Windows Server 2008 R2 Service Pack 1 (SP1).

You run a virtual machine on the computer.

You use a network adapter on the virtual machine to access a network.

You establish many concurrent network connections. Or, there is heavy outgoing network traffic.

In this scenario, the network connection on the virtual machine may be lost. Additionally, the network adapter may be disabled. Notes

You must restart the virtual machine to recover from this issue.

This issue can also occur on versions of Windows Server 2008 R2 that do not have SP1 installed. To resolve the issue, apply the hotfix that is described in one of the following Microsoft Knowledge Base articles:

974909 The network connection of a running Hyper-V virtual machine is lost under heavy outgoing network traffic on a Windows Server 2008 R2-based computer 2264080 An update rollup package for the Hyper-V role in Windows Server 2008 R2: August 24, 2010